Small Engines (Lawn Mowers, etc.): oil change, rear tine tiller, gray gap

Question
I have a craftsman rear tine tiller model#917-293490. Where do I put the oil in at? the tiller has a yellow oil fill cap and also a gray cap above it. What is the gray cap for?

Answer
Do you have a Briggs and Stratton engine...it should according to the parts diagram.  You can fill the oil through the yellow dipstick tube.

The gray gap may be another fill point as Briggs often puts two fill locations on horizontal engines for re-power applications.  Re-power is basically replacing an old engine with a new engine.  The second fill location provides options for re-power applications.

Can you send me a picture of the gray cap?

Eric